diff --git a/programs/test/benchmark.c b/programs/test/benchmark.c
index 0ec2b45..ca08f54 100644
--- a/programs/test/benchmark.c
+++ b/programs/test/benchmark.c
@@ -45,6 +45,7 @@
 #else
 
 #include <string.h>
+#include <stdlib.h>
 
 #include "mbedtls/timing.h"